Introduced into a guillotine valve

ABSTRACT

A guillotine valve, used for example in pipelines, is described herein as including a single block body incorporating sealing elements, each in the form of an annular hose section, which are made of an elastomeric material and which are hollow along their entire circumference, each providing an airtight pneumatic circumferential chamber filled with air. Due to the compressibility of the chambers the contact faces of the hose sections deform uniformly in relation to a closing blade. Convex contours on the internal faces of the hose sections result in a further sealing effect due the pressing together of the contact faces by the pressure of the pipeline fluid. The hose sections can each also incorporate a T-shaped metal core comprising an axial portion and a radial portion.

The present description refers to an Invention Patent dealing with animprovement introduced into a guillotine valve, also known as slidevalve or gate valve. The valve in question, regardless of its variousdenominations, is used as a means for controlling a flow in pipelineswhere dense fluids or fluids containing a large amount of solid materialare circulating.

In synthesis, the guillotine valves work by the principle of dislocatinga closing blade traversing the valve body, thus closing the fluidpassage through the same. Generally, the closing blade can be moved invarious forms, its actuating can be manual, hydraulic, pneumatic or evenelectric.

The conventional guillotine valves present annular sealing means mountedon the valve body and establishing a direct contact with the faces ofthe closing blade when the latter is fully advanced, thus producing theobstruction of the fluid, and further assuring the sealing of thepipeline when the mentioned blade is fully withdrawn; the valves inquestion can be of the passing gate and of the non passing gate type.

In spite of their simplicity and widespread use, the guillotine valvespertaining to the state of the art present aspects which can beimproved, mainly with respect to the sealing means employed in the same.

The objective of the present patent is to provide an improved guillotinevalve presenting a more efficient sealing system than the conventionalones.

Facing the state of the art pertaining to the question and having inview the objectives proposed, has been developed the now proposedguillotine valve, which will be described in detail with reference tothe drawings listed below, where:

FIG. 1 illustrates a side view with a partial cross section of the nowproposed guillotine valve, which is shown in its fully open state, i.e.,with its closing blade fully withdrawn;

FIG. 2 illustrates a front view of the valve hereby dealt with;

FIG. 3 illustrates an enlarged detail from FIG. 1, such as indicated bythe arrow A; and

FIG. 4 illustrates a detail similar to that of FIG. 3, representing thestart of the advance of the closing blade.

According to what is shown on the figures listed above, the guillotinevalve, which is the object of this invention patent, comprises basicallya single metal body 1, of single block construction, on top of which ismounted a sustaining structure 2, which for its part receives themechanic actuation assembly of the closing blade 3. In the specific caseof FIG. 1 there is illustrated, as a mere example without limitations,the use of an actuator 4, which can be either hydraulic or pneumatic,which at the extremity of its telescope rod 5 has mounted the extremeupper portion 6 of the closing blade 3.

The employment of the actuator 4 shall be understood as one of the manyactuating modalities which can be used in the present case, and whichfor this reason is not the focus of the present invention patent.

The single block body 1 is normally assembled between two sectors of apipeline, through which circulates the fluid which eventually shall beobstructed by actuating the valve in question.

The single block body 1 incorporates on each of its two faces, i.e.,downstream or upstream with relation to the flow direction of the fluidpassing the valve, two sealing elements 7, mounted in a fully oppositeform and in mutual contact.

The sealing elements 7, also called hose sections, are manufactured fromelastomeric material, presenting the feature of being interchangeable.

The hose sections 7, as is well illustrated by the figures integratingthis invention patent, are fully hollow in their whole constructioncircumference, having a constructivity permitting their controlleddeformation in function of their particular design, a fact whichpromotes their better accommodation as the closing blade 3 advances,thus actually assuring a more efficient sealing.

The hose sections 7, due to the fact of being hollow, count with asealed circumferential pneumatic chamber each 8, filled with air.

Due to the fact of being pneumatic, the chamber 8 permits that thecontact face of the hose section 7 can be deformed in relation to theclosing blade 3 in a more uniform way, a condition obtained especiallydue to the compression effect of the air volume contained inside thementioned chamber 8 in each one of the two hose sections 7. Suchcontrolled deformation is verified especially when the closing blade 3starts its movement between the hose sections 7.

In other words, the closing blade 3, when advancing between the hosesections 7, promotes the progressive elevation of the air pressurecontained inside the pneumatic chambers 8 of each one of the referred-tohose sections, thus assuring a higher efficiency of the direct contactbetween the contact faces and the surface of the closing blade faces 3.The pressure elevation of the pneumatic chamber 8 in function of thedeformation caused by the closing blade 3 increases also the sealingeffect caused by the hose sections 7 on the mentioned blade,consequently raising the efficiency of the valve actuation as a whole.

The fact of the pneumatic chamber 8 being circular causes the airpressure elevation in its interior to exercise a fully uniformcompression along the total circumference of the hose sections 7.

The hose sections 7 further distinguish themselves from the sealingeffect pertaining to the state of the art due to the fact of presentinga convex contour of their internal faces 9, a format which causes theproper pipeline fluid pressure to provide an increment in the resultingforces acting in axial flow direction, considerably reducing the needfor previous compression of the referred-to hose sections and assuring atotal seal while the valve remains open to the passage of the pipelineflow.

The hose sections 7 present further another aspect distinguishing theirparticular constructivity from the constructivity pertaining to thestate of the art, i.e., the fact of incorporating, each one, a “T”shaped metal core 10.

Each metal core 10 is composed of two independent portions, indicated bythe reference numbers 11 and 12. The function of the tubular portion 11is to provide rigidity to the seal, while the other portion 12, whichhas the form of a disk, acts as a distribution ring of the loadexercised by the pipeline flanges (not shown), thus dismissing the useof external rings, normally recommended to be placed between thepipeline flanges and the valves presently available on the market.

The hose sections 7 integrating the present invention patent areproduced by specially designed molds for the identical reproduction ofthe parts, thus assuring a rigorous standard of shape and dimension,from which results their quality.

The hose sections 7 have been designed to present a more easyreplacement in case of wear and their assembly and disassembly can beperformed without the need to disassemble the valve, a fact which makesthe field operation easier.

The valve herewith proposed also incorporates sliding rings 13,manufactured from wear resistant plastic material. The sliding rings 13are installed in corresponding circular grooves 14 defined in the singleblock body 1 of the valve now proposed, such as can be seen better onFIG. 4, having been designed to assure a perfect sliding of the closingblade 3 during the opening and closing process of the valve.

The sliding rings 13 have the function of avoiding any possibility of adirect contact between the closing blade 3 and the housing 15 of thesingle block body 1.

As occurs with the hose sections 7, also the sliding rings 13 have beendesigned to be replaced in case of wear without the need to disassemblethe valve, rendering the field operation easier.

The sealing means of the valve now dealt with also count on an uppersealing system 16, formed by a part 17 obtained from an elastomericcompound, which is associated to a metal reinforcement 18.

The upper sealing system 16 presents three purposes which are: a) toassure full tightness as to the occurrence of leaks at the upper part ofthe valve; b) to avoid the entering of strange matter which may haveadhered to the closing blade 3 while the valve had been open during theclosing process of the valve; c) to provide to the closing blade 3 thenecessary lubrication for reducing the friction between the same and theelastomeric seals, thus assuring an easy and smooth operation,regardless of the type of actuation employed or even of the environmentin which the valve shall operate.

The upper sealing system 16 counts further with two grease nipples 19,of which only 1 can be seen on the cross section of FIG. 3.

The grease nipples 19 are mounted directly through the metalreinforcement part 18 and communicate with the internal region of theelastomeric sealing part 17 where the cavities 20 are located by achannel 21. Thus, the volume of grease of the cavities 20 can becompleted without need to disassemble the valve.

The metal reinforcement part 18 is attached to the valve body 1 by meansof the bolts 22, as can be also seen on FIG. 3.

As shall have become clear and evident, the guillotine valve nowproposed presents a series of constructive aspects which distinguishesthe same from the state of the art.

1-7. (canceled)
 8. A guillotine valve, comprising: a body; and twosealing elements mounted oppositely and in mutual contact; wherein thesealing elements are interchangeable, hollow in construction andproduced of elastomer; and wherein each one of the sealing elementsincludes a pneumatic circumferential watertight chamber entirely filledwith air.
 9. A guillotine valve according to claim 8, wherein thesealing elements include a convex contour in their internal faces.
 10. Aguillotine valve according to claim 9, wherein the convex contour of theinternal face of each one of the sealing elements provides an incrementin a resultant of forces that act in an axial direction of flow.
 11. Aguillotine valve according to claim 8, wherein each sealing elementincorporates a metallic bore in a form of “T”, each metallic borecomprising two independent portions, a tubular portion to providestiffness to the sealing element and a disk portion which actuates as aring to distribute a load exerted by pipe flanges.
 12. A guillotinevalve according to claim 8, further comprising sliding ringsmanufactured of a plastic material resistant to wear; the sliding ringsbeing installed in corresponding ring-like cavities defined in a housingof the mono-block body.
 13. A guillotine valve according to claim 8,further comprising an upper sealing system comprising a piece having anelastomeric body, which is mounted on a metallic reinforcement, andgrease applying devices directly mounted through the metallicreinforcement piece to be in communication through a channel to cavitiesat an internal area of the elastomeric sealing piece, wherein themetallic reinforcement piece is fixed to the body of the valve by meansof screws.